Stems - From a woody caudex and thick roots, to +/-40cm tall, erect to ascending, herbaceous, fistulose, mostly green but purple at the base, glaucous, sparse to moderately pilose. Trichomes of the plant multicellular.

Other info. - This striking plant can be found in the east-central portion of the state and in a few southwestern counties. It is simple to identify because of its paired leaves, brilliant yellow flowers, and bristly fruits. The species is also cultivated and grows well in many conditions.

Photographs taken in the Ozark Scenic Riverways, Shannon County, MO., 5-12-03, and in Columbia, MO., 4-15-04.